The presence of fracture roughness and the occurrence of nonlinear flow complicate the fracture flow process. In the present study, water flow tests were conducted to comparatively study the flow behavior in smooth (Joint Roughness Coefficient (JRC) = 0–2) and rough (JRC = 18–19) fractures. The confining stress is in the range of 2–60 MPa and the injection pressure is in the range of 0.1–12 MPa to ensure obtaining a wide range of experimental data points. Surface roughness parameters (R_p, Z₂, JRC) based on a single fracture surface and aperture distribution based on both surfaces were calculated and their effect on the flow behavior was explored. Transmissivity, flow regimes and the Forchheimer coefficient β were analysed in detail. The results show that the mean aperture size of tensile fracture is lightly smaller than that of cut fracture, with a much smaller standard deviation. Tensile fracture also has a higher peak frequency, indicating that the two fracture surfaces match more perfectly. The intrinsic transmissivity ratio of cut to tensile fracture increases from 1.6 under 2 MPa to 9740.7 under 60 MPa, which may be attributed to the fact that cut fracture has an about \(1/30\) stress-dependence coefficient λ of the tensile fracture. Flow data for cut fracture scatter in transition and turbulent flow regions while scatter in laminar and transition flow regions in tensile fracture, and it is supposed to be quite difficult for flow in tensile facture to enter into turbulent flow. For tensile fracture, a linear relationship exists between Forchheimer coefficient β and mean aperture size η (\(\beta = a_{1} \eta + b_{1}\)) and the correlation coefficients is up to 0.988, while for cut fracture, an exponential model relating β with both confining stress and mean aperture size η was proposed (\(\beta = a_{2} e^{{\left( {b_{2} - c_{2} \eta } \right)^{\sigma } }}\)) and the correlation coefficients is up to 0.978.

裂缝粗糙度的存在和非线性流动的出现使裂缝流动过程变得复杂。在本研究中，进行水流试验来比较研究光滑裂缝（接头粗糙度系数（JRC）= 0-2）和粗糙裂缝（JRC = 18-19）中的流动行为。围压范围为2-60 MPa，注入压力范围为0.1-12 MPa，以确保获得广泛的实验数据点。计算了基于单个断裂面的表面粗糙度参数（R _p、Z ₂、JRC）和基于两个表面的孔径分布，并探讨了它们对流动行为的影响。详细分析了透射率、流态和 Forchheimer 系数β 。结果表明，拉伸断裂的平均孔径尺寸略小于切割断裂的平均孔径，且标准差也小得多。拉伸断裂也有较高的峰值频率，表明两个断裂面匹配得更加完美。切割与拉伸断裂的固有透射率比从2 MPa下的1.6增加到60 MPa下的9740.7，这可能归因于切割断裂具有约“ 1/30”的拉伸断裂应力依赖性系数λ 。 。切割裂缝的流动数据在过渡区和湍流区是分散的，而拉伸裂缝在层流区和过渡区是分散的，并且拉伸裂缝中的流动很难进入湍流。对于拉伸断裂，Forchheimer 系数β与平均孔径大小η之间存在线性关系（\(\beta = a_{1} \eta + b_{1}\) ），相关系数高达 0.988，而对于切割断裂，提出了将β与围压和平均孔径尺寸η相关联的指数模型( \(\beta = a_{2} e^{{\left( {b_{2} - c_{2} \eta } \right) ^{\sigma } }}\)）相关系数高达0.978。